Wing-tip float structure for aircraft



Dec. 14, 1948. l G. A. SMITH WING TIP FLOAT STRUCTURE FOR AIRCRAFT Filled May 5, 1945 AT-rozuey Patented Dec. 14, 1948 OFFICE.-

WING-*TIP FLoAT STRUCTURE FOR f AIRCRAFT Glenn A. Smith, United States Navy Application May 5, 1945, Serial No. 592,157

' ,I (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 O. G. 757) 3 Claims.

kThis invention relates yto new and useful improvements in@ iioat structures for aircraft, and e more'particularly to wing tip i-loat structures for `seaplanes, amphibious aircraft and the like, i f-'It -is"-the customary practice to provide lsea- "planes, amphibious and like aircraft with float structures at the underside of the wing adjacent the tips or ends thereof for the purpose of providing lateral stability to the plane during takeoff andlanding thereof onl-water and to prevent the tips of the wing from contacting or striking the water with resulting damage thereto and to the plane. Prior to the present invention ysuch float structures generally have been either secured permanently in a fixed position beneath the `wing -of the plane, or have been pivotally mounted for movement between a lowered position beneath the wing for contact with v.thewater and a raised or elevated position in v'which the float-is disposed endwise of the wing forming the tip or end section thereof. Both of these arrangements are aerodynamicallyinefficient and objectionable.I In the type -of float structurerst mentioned, the xed float e isr designed and contoured primarily to providef optimum hydroplaning action when in contact Iwith the` Water and therefore does not provide an efficient streamlined form yhaving a small 'frontalarea that presents a minimum amount `of vresistance to the air when the plane is in flight. Onthe other hand,in the second type of float structure, the float or hull which' likewise is contoured to provide optimum hydroplaning Aaction in water, when lowered for use during take-off or landing, does not provide an eilicient aerodynamic surface when in the raised or ele- 'vated' position endwise of the wingk and forming the tip or end section thereof.

With the foregoing in mind, it is the principal object of lthe present invention to provide a novel wing tip float structure for aircraft that 'provides optimum hydroplaning action in water during take-off and landing, and provides an ecient streamlined form presenting a small frontal area with minimum resistance to the air when the plane is in flight. y

Another object of the invention is to provide a novel wing tip `float structure having the stated characteristicsk comprising a hull member which `is selectively positionable relative to the surface of a body/of waterl to provide optimum hydroplaning action of the member in the water.

A further objectof the present invention` is to provide a novel' wing tip structure of the stated.chara .r.=terv comprisinga zhousing shell havwater during take-off and landing 4of the plane.

These and other objects of the invention and the various features and details of thefconstruction and operation thereof are hereinafter fully set forth and described with reference to the accompanying drawing, in which:

Fig. 1 is a side elevation view of a wing tip float structure for aircraft embodying the present invention.

Fig. 2 is an enlarged sectional view taken on line 2 2, Fig. l; and f Fig. 3 is an enlarged sectional view takenon line 3 3, Fig. 1.

Referring now to the drawing, and more particularly to Fig. 1 thereof, reference numeral "I designates the wing structure of a seaplane, amphibious or like aircraft, and numeral 2 .generin accordance with the present invention which comprises, in the embodiment shown, a'housing shell or shield member 3 and an associated hull ymember 4, suitably supported lbeneath the'plane wing structure I adjacent the outer ends or tips thereof. i .f

The housing member 3 of the vfloat 'structure 2 is of/generally inverted U, or upwardly arched, cross-sectional shape that tapers gradually rear'- wardly to a point as shown, yand this housing vmember 3 may be supported beneaththefplane wing structure I in the relation shown, for example, by means of suitable pairs of struts or the like 5, 6 and 1, respectively. The struts5 may have their upper ends secured to the underside of the wing structure I and extend vertically downward with their lower ends secured to the float structure housing member '3 `at vopposite sides thereof adjacent the forward endby means of bolts, rivets or like fasteners 8, while the struts t may have their upper ends similarly lsu/secured to the wing I and extendangularly downward to the housing member 3 with their lower ends likewise secured thereto byjmeans The pair of struts 'I support the housing member 3 toward the rear end thereof, and these may be secured to the undery'side of the wing I and decline angularlyv-therefrom as shown with their lower ends secured together, for example, by means of a bolt, rivet or like fastener 9. The connected end portions of the struts i may extend inwardly of the housing member 3 through an opening formed centrally therein,` with respect to the sides of the member 3, for a purpose hereinafter set forth, and the housing member 3 may be' welded or otherwise permanently secured to said strutsi as indicated at I l). In addition to the pairs of struts 5, 6 and l, the float structure may be supported and braced against the drag of water. thereon in the fore and aft direction ,byl means of guy wires, rods or the like il arranged, for example, as shown in the drawing` The hull member Il of the wing tip float structure 2 is constructed and arranged for pivotalE movement relative to the xed housing member 3 between a raised or elevated position nesting within the housing 3 as shown in solid lines in thedrawing, anda selected lowered position with irespect tosaidhousing wherein the after portion .of .the hullmember is presented to the surface lof thefwater, for example, as shown in dottedlines `in. Figs. .l and 3, to provide optimum hydroplaning .actionner `said hull `member i in the water.. To this end, the hull member c oi the float structure `2 is pivoted, adjacent its forward end, to the housing member 3 and the aforesaid fasteners ii ,may be employedand utilized for this purpose in the manner shown in Fig. 2 of the drawing.

.In-accordance with the present invention the hull member li may be lowered and elevated rela- Ytive :to the housing member 3 of the float struc.- ture about the `fastener pivots 8, for example, by: :suitable hydraulic Ameans comprisingy a cylinder 412 having therein a piston i3 provided with a connecting or piston rod IQ that projects outfwardly of one end of said cylinder i2. rfloiscylinder-piston assembly may be operativelyinten; iconnected vbetween the housing member ir and hull member d, to raise and lower thejlatter rela- .tive to the housing, in the manner best'shown in Fig, 3 of the drawing, by pivotally mounting the closed end `of the cylinder I2 for limited pivotal' movement upon the fastener d in a fore and aft direction, .and pivotally connecting the free end of the piston ,rod I4 to a suitable standard I5 that is il-Xedly secured to the interior of the bottom iwal] portion of the hull member il.

Fluid may be .selectively introduced into the icy1inder12 at opposite sides of the piston I3 by means of suitable pipes or tubes iii and i?, re- `ispectively, to lower and elevate the hull member `ll vrelative ltoit-he .housing member 3, and by regudating the -uid introduced into the cylinder I2 through pipe I6 to lower the hull member Il, the

:position of the latter 'may be controlled in order that the hull .member may be presented to the surface of the water 'to provide optimum hydro- -planing action thereon.V The top wall portion of nthe -hull member l is provided with a suitable `opening I8 therein so that said hull memberrnay clear 'the cylinder I2 whenthe piston i3 therein is actuatedto lower the hull member il relative to the housing member 3, and means, suchA as bel- V:lows I9 may be provided between the housing Aand hull members about the opening Iii to prewent the entrance ofwater into the hull member.

In operation of al wing tip iioat structure madef according to the present invention, vwhen aircraft equipped therewith is at rest l.upon the sur- `face of a body of water,"the hull members d of the wing tip iloats adjacent opposite ends of the v "wing 'are maintained in a lowered position relative to their housing member 3 in contact with the water by maintaining a predetermined quantity of fluid in the cylinder I2 above the piston I3 of each float structure, and when taking off from the surface of the water the hull members 4 are positioned and adjusted to provide optimum hydroplaning action thereof. upon theu water by varying the position ofthe piston I3 as required.

When the plane is airborne, the hull members fi of the wing tip float structures are elevated and nestedjw'ithin their associated housing members 3 byreleasing the pressure in the pipe IB and introducing suincient nuid into the cylinder I2 through pipe il to raise and maintain the hull .members 4 in the position shown in solid lines in Figs. i and 3 of the drawing. The contours of the housing member 3 and thehull member 4 are such that when the vlatter is elevated and nesting within the housing member 3, the float structure presents an efficient streamlined form having a small frontal Zarea that aords minimum .resistance to the air .when the plane is in flight.

.As the plane descends preparatory .to making. a landing on water, the Yhull members Il are ,lowered relative .to their housings .3v so as to engage with the water by.` releasing fluid .from vthe cylinder through pipe Il, and introducing sufficient .fluid into the cylinderIzZ through .the ypi-pe I6 to actuate the piston E3 yand its 'rod I4 downwardly lwith .referencer to Fig. 3, the particular lowered position of the hull members .4 that -is vdesired-for optimum hydroplaning action thereof on the water being obtainable as required Yby controlling the position of the vhull members 4 withy respect to their housings 3 through regulation of the amount of uid within -the cylinder I2 that. is acting .on the piston I3. Y k Y f y g From the foregoing it will .be-observed that the present invention provides Va Wingtip float structure for seaplanes, amphibious and xlike aircraft that is constructed and Varranged Itoprovide optiniumhydroplaning vaction in water .during takeoff and landing of the .pl-ane. and whichfprovides an eoient streamlined form presenting :a .small frontal area with minimum resistance to `the air when the plane is -in flight. The invention also provides a wing tip floatl structure having .the stated characteristics comprising a hull .member in, it is not vintended that the-finventorbe limited to such disclosure, and changes land modifications -may be made. therein and 4thereto within -thescope of the claims.

i The invention described herein .may betm'anufaotured and used by or forfthe Government. :of fthe United States .or America .for `governmental Ypurposes withoutthe payment :of `any royalties `thereon or therefor.

l claim:

i l. For useon an airfoil, .at least -one pair of strut structures and a single strut structure, the

respective structures depending .rigidly .from the 1 'irfoil and spaced in the front to rear` direction, a cover occupying a position between the-strut structures, being aiixed to the rear strut :structure and extending into approximation Aiwitl'i the pair of front strut structures, a :hull memberun- 'derlying the cover and partially :housed thereby,

fastener means rigidly .securing the front `of the -cover to the pair of .struts and simultaneously supporting the hull member for pivotal movement in respect to the cover, and telescopically contrived pressure fluid-operable means having its relatively movable components respectively pivotally attached to the hull `and to the rear strut structure.

2. For use on an airfoil, at least one pair of strut structures and a single strut structure, the respective strut structures depending rigidly from the lairfoil and spaced in the front to rear direction, a cover occupying a position between the strut structures, having an opening through which the terminal of the rear strut structure extends to render it accessible, said cover being axed to the rear strut structure and extending forwardly into approximation with the pair of front strut structures, a hull member underlying the cover and partially housed thereby, fastener means rigidly securing the front of the cover to the pair of struts and simultaneously supporting the hull member for pivotal movement in respect to the cover, and telescopically contrived pressure fluid-operable means having its relatively movable components respectively pivotally attached to the hull member and to said accessible terminal of the rear strut structure.

3. A Wing tip iioat comprising a hollow twopart body consisting of a hull member and a cover respecting which the hull member is partly nested, means rigid relatively to the oat constituting the common forward iixing point for the cover and pivot for the hull member, telescopically contrived pressure uid-operable means having one of its relatively movable components pivotally attached to the hull member, and a combined anchor for the rear of the cover and point of pivotal attachment for the other component of the telescopic means.

' GLENN A. SMITH.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS 

